Debugging Javascript with a Reverse Proxy

A few months ago I was exploring the possibility of integrating IBM's Lotus Sametime instant messenger into an installation of Websphere Portal 7 and I had to test some cross domain javascript. As we all know, modern browsers won't allow a javascript request to access a domain which is different from the current.

In this case the javascript provided by the sametime proxy server (running on a different node) contained relative URLs, like /stwebapi/..... Now this is not an issue when running in a production environment because we have a Webseal reverse proxy, but if you need to debug some code on a local machine then you're out of luck. The browser won't issue cross domain javascript requests.

Using Apache as a Reverse Proxy

Turns out that with a few configuration tweaks I can use apache as a reverse proxy. I added the following lines to the bottom of my \Apache2.2\conf\httpd.conf :

ProxyRequests Off

Order deny,allow
Allow from all

ProxyPass /stwebapi http://ghprd01:9081/stwebapi
ProxyPassReverse /stwebapi http://ghprd01:9081/stwebapi

So now any requests to /stwebapi will be redirected to by apache to http://ghprd01:9081/stwebapi, and as far as the browser knows it all comes from the same domain.

Piece of cake!